Safety device for metal sheet conveyers in tin-plating apparatus



Dec. 13, 1949 H. c. KIRK SAFETY DEVICE FOR METAL: SHEET CONVEYERS INTINPLATING APPARATUS Filed May 12, 1947 II mun INVENTOR. lid/PR) C KIRK.

Patented Dec. 13, 1949 I UNITED Mantis SAFETY DEVICE FOR METAL SHEETCON- VEYEBS IN mm 0. Kirk, Weh'ton, w.

National Steel Corporation, a

Delaware TIN-PLATING APPABA TUS Va., a-ignor to corporation ofApplication M87 12, 1947, Serial No. 747,429

Claims. (CL 91-12.7)

The present invention relates to improvements in apparatus for conveyingsheet material along a path and more particularly relates to suchapparatus including a safety device for stopping the passage only ofdeformed or irregular sheets through the apparatus.

The present invention will be described more particularly in connectionwith hot dip, tinplating apparatus for producing tinplate although itsprinciples may be applied to other types of apparatus in which sheetsare propelled along a. path by power-actuated rolls or other means.

In mills where tinplate is produced by the hot dip process. the flatsheets of base metal, ordinarily sheets of black plate, aresuccessively. rapidly and continuously moved through the tinapplyingapparatus by means of series of guides and power-actuated feed rolls.The tinned sheets, as they emerge from the plating apparatus, areengaged by the first pair of a series of catcher rolls. The catcherrolls propel the s eets of tinplate to the branning machines and/orother processing apparatus. moved through the tinplating apparatus, itwill be bent, wrinkled or deformed so as to have a shape different fromthe normal flat shape. These deformed sheets are called cobbles. Acobble may occur in the tin pot by the sheet being improperly fed intothe tinning apparatus in a biased or canted position. Most cobbles,however, are formed at the catcher due to the fact that the sheets mustpass through an open space at this point so that cooling air can beimpinged upon them. A cobble at the catcher causes cobbling in the tinpot due to jamming of the succeeding sheets one on the other. As aresult, it is necessary to remove the entire machine from the while thetinning and line and replace it with another machine containing thecobbles is repaired the cobbles removed.

Accordingly, a primary object of the present invention is to provide animproved sheet conveying apparatus which includes means for guidingnormal sheets along the path of sheet movement and for stoppingautomatically the feeding apparatus upon receiving a cobbled sheetwhereby damage to the apparatus and the formation of additional cobblesis prevented.

It is also an object of the present invention to provide a safety devicefor hot dip, tinplating apparatus which includes means for guiding flat,normal sheets from the grease pot rolls to the catcher rolls and forstopping the grease pot rolls when a sheet is deformed in the platingapparatus Occasionally, as a sheet is catcher rolls.

.2 A to prevent feeding the deformed sheet to the These and otherobjectsand advantages will become more readily apparent from thefollowing ,rallty of outlet passages detailed description taken inconnection with the accompanying drawings in which:

Figure 1 is a sectional view taken longitudinally of apparatus embodyingthe present invention in which the front portion of the apparatus hasbeen removed to more clearly show the internal structure;

Figure 2 is a transverse, fragmentary sectional view taken along line2-2 of Figure 1; and,

Figure 3 is an enlarged, fragmentary view of the switch and itsoperating mechanism taken as indicated by line 3-3 on Figure 2.

Referring more particularly to the drawings showing a preferredembodiment of the present invention, the hot dip tinplating apparatusincludes a tank It through which sheets H are successively passed andcoated with molten tin. Sheets II are flat sheets of ferrous metalordinarily containing a low percentage of carbon and commonly referredto as black plate.

The tank It includes a lower compartment or tin pot l2 in which there ismaintained a molten pool of tin. A pair of upper plate members l3 extendacross the tank It to form a flux pot M in which thereis maintained abody of liquid flux. A grease pot I5 confines a pool of grease, such aspalm oil, on top of the pool of molten tin. Power-actuated, rotatablefeed rolls I! are provided for feeding sheets ll one by one into thetank It. Power-actuated feed rolls l8 are rotatably mounted in the tinpot l2 and rolls l8 and the two guide members l9 and 20 guide sheets llthrough the pool of molten tin.- Three pairs of power-actuated feedrolls 2|, 22 and 23 are rotatably mounted in grease pot It for feedingthe sheets up through the palm oil. These feed rolls 2|, 22 and 23 arealso wiping rolls and, at least to a certain extent, control thethickness of the tin allowed to remain on the sheet II by removing thetin which is in excess of the predetermined amount desired.

The tinplating apparatus includes a pair of upwardly extending sideframe members 24 and 25 in which are mounted a pair of horizontal pipes21, 28, each connected through a hose 29 to a source of air or otherfluid under pressure. The pipes extend transversely of the oppositesurfaces of the strip and each pipe is provided with a, plu- 32 fordirecting streams of air against the corresponding surface of the hot,plated sheet as it emerges from the grease pot I! to cool and solidifythe tin coating. A plurality of power-actuated catcher rolls 35 arerotatably mounted in the frame members 24 and 25 for propelling thesheets further along the path of sheet movement to the guide member 31.

Sheets of pretreated black plate are either manually or mechanically fedsuccessively to the tinplating apparatus. Any suitable sheet feedingapparatus may be used. The rotating feed rolls l'l pass the sheet downthrough the flux pot l4 and into the tin pot l2 where the rotating rollsI8 move the sheet through the pool of molten tin.. The guide 20 bendsthe leading edge of the sheet upwardly so that it enters the nip of thefirst pair of grease pot rolls 2|. The grease pot rolls 2|, 22 and 23remove the excess molten tin and pass the sheet upwardly between thecooling pipes 21 and 28 until the leading edge of the sheet is grippedbetween the catcher rolls. The catcher rolls 35 move the sheet furtheralong its path of movement through the mill.

As the leading edge of the flexible sheet H is pushed upwardly by thegrease pot rolls toward the catcher rolls, the uppermost portion of thesheet needs to be supported and guided toward the catcher rolls 35. Aguide means is provided for guiding the sheet II from the grease potrolls to the catcher rolls. Opposed, divergent, depending guide membersor fingers 39 and 40 are mounted on and connected to correspondingsquare shafts 4|, 42. The shafts 4| and 42 are pivotally supported inthe side frame members 24 and 25 so that each shaft and the dependingguide fingers are pivotally movable about an axis parallel to the sheetand normal to the direction of sheet travel. A spur gear 45 is connectedto the shaft 4| and a meshing spur gear 44 is connected to the shaft 42so that the shafts 4| and 42 turn in unison. An outwardly extendinglever 46 is connected to the shaft 4| and a stop 41 is mounted on theside frame member 24. Stop 41 stops rotation of the shafts 4| and 42 ina direction to move the opposed fingers 39 and 40 toward each other sothat the fingers are maintained in position to guide and allow thepassage therebetween of normal, flat sheets.

A normally closed switch 48 is mounted on the side frame member 24 andis operably connected to the drive means for driving all of the feedrolls. A common drive means of the type customarily used in hot dip,tinplating machines rotates all of the feed rolls l1, l8, 2|, 22 and 23and the catcher rolls 35 at the same peripheral speed, a portion of thisdrive means is beneath cover 49, Figure 2. A downwardly extending,vertically movable plunger of switch 48 is provided at its lower endwith a roller 5| engaging lever 46. A compressed spring 52 extends aboutplunger 50 between the switch 48 ,and an adjustable nut 53 threadedlyengaging the plunger 50. The spring 52 presses the plunger 50 and thelever 46 downwardly to maintain the switch 48 in the normally closedposition and to urge the divergent guides 39 and 40 toward eachother asfar as stop 41 will permit. The spring 52 resiliently urges the guides39 and 40 into the normal position for guiding fiat sheets from thegrease pot rolls to the catcher rolls. The force urging the guides 39and 40 toward each other to the sheet-guiding position can be changed.by adjusting nut 53 to vary the pressure exerted by spring 50- and byvarying the effective length of lever 46.

As a fiat sheet is moved up between the guides 39 and 40, the guidesguide the sheet into the nip of the lower pair of catcher rolls. Thestop 41 may be positioned so that the guides are spaced apart a distanceequal to or greater than the thickness of a sheet or, the stop 41 may bepositioned so that the guides are spaced apart a distance slightly lessthan the thickness of a sheet. In any one of these positions, the guides38 and 40 provide some support for and act as guides for the flat sheetsand the passing of a flat sheet between the guides while so positioneddoes not move the guides 39 and 40' sufficiently to actuate the switch48.

As an enlarged deformed portion of a deformed sheet enters theconvergent throat between the guide members 39 and 40 and starts.

to pass between the divergent guide members 39 and 40, these members arespread apart which in turn raises lever 46 and plunger 50 to open theswitch 48 and stop all of the feed rolls. The deformed sheet is removedand the apparatus then restarted. Thus, the guides 38 and 40, when inthe normal orsheet guiding position, are arranged to guide the normalsheets being fed upwardly by the grease pot rolls and are movablysupported for movement to a different position upon receiving a deformedsheet from the feed rolls. The guides and the switch constitute a safetydevice for stopping the feed rolls when a deformed sheet is received bythe guides to prevent damage to the catcher rolls and other equipmentand to prevent the feeding of additional sheets through the apparatusuntil the deformed sheet has been removed. Further, without this safetydevice, the presence of a cob-, ble in the catcher rolls causes cobblesin the feed rolls and as it is impossible to remove these cobbles, ithas in the past been necessary to remove the entire machine from theline and replace it with another while the tinning machine containingthe cobbles was repaired and the cobbles removed. The guides also reduceor elimmate the number of cobbles formed at the catcher rolls as aresult of improper positioning of the leading edge .of the sheet so thatthe leading edge does not properly enter the catcher rolls.

I claim:

1. In hot dip tinplating apparatus, the combination comprising, meansfor successively hot dip plating a series of sheets, power-actuated feedrolls for propelling the plated sheets upwardly from the plating meansalong a path, power-actuated catcher rolls disposed above the feed rollsfor advancing the sheets further along the path, opposed guide members,a pair of shafts supporting the guide members on opposite sides of thepath of sheets between the feed rolls and the catcher rolls in a normalposition in which the guide members are arranged to guide a normal sheettherebetween along the path to the catcher rolls, each shaft beingrotatable about an axis extending parallel to the sheets andtransversely of the direction of sheet travel and the shafts movablysupporting the guide members for movement through an are away from thepath and each other to a different position upon receiving a deformedsheet from the feed rolls, means resiliently urging the guide memberstoward the normal position to support and guide the normal sheets. andproviding restrained movement of the guide members to said differentposition, and control. means mechanically engaging andoperable bymovement of the guide members all the way to said different position tostop the feed rolls whereby the feed rolls are stopped of the path ofsheets deformedsheettothenude 2*. In hot dip tinplating apparatus, thecombination comprising, means for successively hot dip plating a seriesof sheets, power-actuated feed rods for piopellingthe plated sheets.upwardly an are away from the path and each other to a differentposition upon receiving a deformed sheet from the feed rolls,

for movement through ,gear means connecting the shafts for rotation ofthe path of in unison in opposite directions, means resiliently I,urging the guide members toward the normal position to support and guidethe normal sheets and providing restrained movement of the guide membersto said different position, and control means mechanically engagin andoperable by movement of the guide members all the way to said differentposition to stop the feed rolls whereby the feed rolls are stopped uponfeeding a deformed sheet to the guide members.

3. In hot dip tinplating apparatus, the combination comprising, meansfor successively hot dip plating a series of sheets, power-actuated feedrolls for propelling the plated sheets upwardly from the plating meansalong a path, power-actuated catcher rolls disposed above the feed rollsfor'advancing thesheets further along the path, opposed guide members, apair of shafts supporting the guidem'embers on opposite sides sheetsbetween the feed rolls and the catcher rolls in a normal position inwhich the guide members are arranged to guide a normal sheettherebetween along the path to the catcher rolls, each shaft means'beingrotatable about an axis extending parallel to the sheets andtransversely of the direction of sheet travel and the shafts movablysupporting the guide members for movement through an arc away from thepath and each other to a different position upon receivinga deformedsheet from the feed rolls, gear means connecting the shafts for rotationin unison in opposite directions, an arm connected to one of the shaftsand movable therewith, a stop engageable by the arm for limiting themovement of the guide members toward each other, a normally closedswitch associated with the feed rolls and operable to an open positionto stop the feed rolls, a switch operating member, and resilient meansurging the switch operating member into engagement with the arm and theam into engagement with the stop to urge the guide members to the normalsheet'guiding position to support and guide the normal sheets to thecatcher rolls and providing restrained movement of the arm away from thestop to, open the switch and restrained movement of the guide members tosaid diflerent position to stop the feed rolls upon receiving a deformedmachine between the guide members.

4. In hot dip tinplating apparatus, the combination comprising, meansfor successively hot dip plating a series of sheets, power-actuatedpower-actuated catcher rolls snaftslo betweenthe'feedrollsand' of sheettravel and 4 the shafts movably supporting the guide members feed,rollsfor propelling the plated sheets upwardly from' the plating meansalong a path, disposed above the feed rolls for advancing the sheetsfurther the path, opposed guide members, means supporting one of the.guide members on one side of the sheet path between the feed rolls andthe catcher rolls in a normal position, a shaft supporting the otherguide memberon the opposite side of the sheet path between the feedrolls and the catcher rolls in a normal position, the

guide members in, the normal positions being arranged toguide a normalsheet therebetween along the path to the catcher rolls, means rotatablysupporting the shaft for rotation about an axis extending in a directionparallel to the sheets and transversely of the direction of sheettravel, the shaft movably supporting the guide member thereon formovement through an are about said axis away from the sheet path and theopposite guide member to a diiferent position upon receiving a deformedsheet from the feed rolls, means restraining movement of the shaftsupported guide member from the normal position to support and guide thenormal sheetsand providing restrained movement of the shaft supportedguide member to said difl'erent position, a control operable to stop thefeed rolls, and control operating means connected to the shaft supportedguide member and movable therewith to a control operating position foroperating the control and stopping the feed rolls upon movement of theguide member to saiddifferent position whereby the feed rolls arestopped upon the feeding of a deformed sheet to the guide members.

5. In hot dip tinplating apparatus, the combination comprising, meansfor successively hot dip plating a series of sheets, power-actuated feedrolls for propelling the plated sheets upwardly from the plating meansalong a path,

, power-actuated catcher rolls disposed above the feed rolls foradvancing the sheets further along the path, opposed guide members,means supporting one of the guide members in a normal depending positionon one side of the sheet path between the feed rolls and the catcherrolls, a shaft supporting the other guide member in a normal dependingposition on the opposite side of the sheet path between the feed rollsand thecatcher rolls, the depending guide members diverging outwardlyfrom the sheet path and defining a convergent throat to receive andguide a normal sheet therebetween along the path to the catcher rolls,means rotatably supporting the shaft for rotation about an axisextending in a direction parallel to the sheets moving along the pathand'transversely of the direction of sheet travel, the shaft rotatablysupporting the guide member thereon for movement through an are aboutsaid axis away from the sheet path and the opposite guide member to adifferent position upon receiving a deformed sheet from the feed rolls,means restraining movement of the shaft supported guide member from thenormal position to support and guide normal sheets and providingrestrained movement of th shaft supported guide member to said diflerentposition, and control means including a control op-- alon . 8 memberarranged so that movement or the shaft UNITED STATES PATENTS supportedguide member to said different positlon moves the control operatingmember to the gg Se B g operating wher by he feed r0115 e Ea ar stoppedonly up n t e f d g f a deformed 5 3 9 sheet to the guide members. Cour1 1 17 HARRY c KIRK 1,809,398 Bean June 9, 1931 2,083,936 Bachhouse June15, 1937 REFERENCES CITED 3 Keller Jan. 4, 1944 The following referencesare of record in the 10 tile 01 this patent:

